This invention generally relates to a color image processing apparatus with image processing functions including resolution correction and color ghost correction, and specially relates to a color image processing apparatus applied to a simple electrophotographic color copying machine in order to obtain satisfactory color image.
The color image processing apparatus optically reads color image information on a document optically, separates the information into multiple colors including black, red and blue, and outputs it through its electro-photographic color copying machine. This type of color image processing apparatus is disclosed in Japanese Patent Publication Open to Public Inspection Nos. 147374/82 and 62769/83.
FIG. 30 shows part of a key assembly of the said color image processing apparatus.
In this figure, color image information is separated into white and cyan colors, each of which is projected onto image sensors 104 and 105 for electrophotographic conversion.
More specifically, white and cyan color signals are supplied to the subtracter 2 where red color is separated. These white, cyan and red colors are gain-controlled by the AGC circuits 3, 4 and 5, respectively, the image processing such as the gamma-correction, etc. are processed by the image processing circuit 10 and then are coded by the binary coding circuits 6, 7 and 8, respectively. The coded output is again converted into red and black color signals by the arithmetic circuit 9, for example, and these signals are supplied to the color copying machine as image signals for color reproduction of the original.
FIG. 31 shows a reversed example of image processing and binary processing.
Incidentally, as kinds of image processing capable of being performed in such color image processing apparatus, color ghost correction, image resolution correction, and image size enlarging/reducing operation may be listed up. Accordingly, in the case where abovementioned processes are carried out, for the purpose of preventing relative interferences in signal processing among these processes and eliminating influences caused by noises, it may be necessary to latch respective signal in the time when respective signal processing is completed. In conventional devices as shown by FIGS. 30 and 31, each of plural color signals obtained by color separation must be independently subjected to a signal processing and a latch treatment. Correspondingly, there is a disadvantage that the circuitry size of image processing circuit 10 inevitably becomes larger. In addition to this disadvantage, in the conventional example as shown by FIG. 30, since a kind of signal to be processed is analog signal, there is a problem that it may be difficult to carry out various kinds of image processing. In the conventional example as shown, by FIG. 31, since a kind of signal to be processed in image processing circuit 10 is binary signal, there is a problem that possible image processing may be limited to enlarging/reducing process.